include <REGX52.H>

void Delay500ms(void)	//@11.0592MHz
{
	unsigned char data i, j, k;


	i = 22;
	j = 3;
	k = 227;
	do
	{
		do
		{
			while (--k);
		} while (--j);
	} while (--i);
}



void main()
{

	while(1)
	{
   
		P2=0xAA;
	  Delay500ms();
    P2=0X00;
	  Delay500ms();
	}	
}